Improvement in extension tables



t t i tdci-'ted CS1-atea @wat @titille THOMAS O. ELLISON, OF HAOLBANY, NEW YORK.

Letters Patent No.' 110,220, dated December 20, 1870. f

IMPROVEMENT IN EXTENSION TABLES.,

The Schedule referred to in these Letters Patent and making pari: 'oi the same.

To all whom it may, concern.-

Beeit known that I, THOMAS O. EnLIsoN, of the cit-y and county of Albany, State of N ew York, have inventedk certain new and useful Improvements in Extension Tables;. and I do hereby `declare that the following is a description thereof, reference being had to the accompanyingdrawing, in which- Figure l represents a vertical view of a table, from beneath, embodying the improvements in this in vention.

Figure 2 is a cross-section of the same through line No. 1 in g. 1.

Figure 3 is a'longitudinal sectional view ofthe operating-screws.

The nature of my invention consists in combining with an extension table one or more screws, working into sleeves, in such a manner that the -said screws, when operated, will be capable of .extending or contracting the length of the table; the' object of this invention being to render an extension table capable of being extended or contracted in its length by .a single person with ease and accuracy of the several'y parts. p

To enable others skilled in the art to make and use my invention, I will proceed to describe it in-reference to the drawing and the letters of reference marked -thereomthe same letters indicating like parts. In the drawing- A represents the legs.

B B are the side rails.

C is a portion of the table-top secured to the said side rails B B.

D vD/are the end pieces, each of which connect the legs Ain pairs.

arev sliding rails, connected with one pair of .legs on their connecting-piece D.,

E F are sliding'rails, Vconnected with .the connectl ing-piece D' of the second vpair of Legs.

a b c d e are the usual tongued and grooved sliding p1eces,which are used in connection with pieces EE, I F, and rails BB in the ordinary manner. `All'of the above devices are old, :md have long been used. y

Tables consisting of theseveral parts arranged as above described requiretwo persons' to effect-an extension or contraction of the length of thc table, and generally more or less labor is required to effect an extensionV of the table in a true line of direction, especially when any of thc sliding pieces are in thc least warped, or work any way binding. l

In myiuventionI use one or more screw-threaded shafts working into sleeves, which screwshait,.when revolved by a crankin a given direction, will cause an extcnsion'of tlic table, and, when revolved in a contrary direction, will cause a contraction ofthe same.

ln the drawing'- Y y S represents a shaft cut with a screw-thread, which `shaft works into the'sleeve G. The said sleeve is cut at its mouth with a screw-thread corresponding with that on the shaft S, and is capable of receiving a major portion of the shaft; and when the length of the sleeve G and the major portion of the shaft is, say, sixteen inches in length, the whole can be extended to alength of about thirty inches, and sleeves and shafts ot' greater or less length can be extended to a proportional length.

As it may be desired in some cases to secure an increased length of extension with a limited length of shaft S and sleeve G, I cut on the outercircurnferencc of the sleeve a screw-thread, and also furnish a second sleeve, H, vinto which the firstsleeve G may work in a manner similar to the shaft S. r v The mouth of the second sleeve H is also furnished with a screw-thread corresponding with that cut on the sleeveG.

'By this arrangement of the. shaft S and the two- .in full shaded lines in fig. 3, and then continuing the revolving of the shaft until the sleeve G will be screwed 'out of the sleeve H lto its' limit, shown by: dotted lines G'.

When one set of suchsleeves G and H with a screw-shaft S is used, I vwould attach the outer sleeve H to one of the end-pieces D by lmeans of the footf, w-hile the outer end of the screw-shaft -S -would be secured tothe opposite end-piece D (shown by outline in iig. 3) by any propel' bearing or collar which would permit the said screw-shaft being revolvcdin the same, and ye't keep it fixed with the said end-piece, D'

When thc end pieces Dy and D' are brought to approach each other as D and (in dotted lines) D', the screw-shaft S is turned (by a wrench or crank W) in a proper direction, the said shaft S will be screwed out of its sleeve G, and in screwing out will cause the distance between thepieces I) and D' to be extended from D and D' (in dotted lines) to D and D', (in out`` linc,) when the shaft has been turncd'out to its full limit, and the turning of the said shaft is continued, the turning of the sleeve G in its slecve ..]-I will be commenced;v and the turning being continued, the

said sleeve G will be screwed out of the sleeve II to near its whole length, and cause further extension ,of

the distance between the pieces D and D', but, inmost Vcases,I prefer to' use thc said sleeves, one or The outer ends of the screw-shafts S S project past the bearings g g, and 'are furnished with miter-gears, J J, which gears are driven by a third gear, K, attached to tliefshaft h, and operated by a wrench or crank, W, from one side of the table, as shown in figs. 1 and 2,.

By turning the crank W (which may be detachable) in a proper direction, the gear K will'causethe gears J J to revolve, and cause the screw-shafts S S to turn out their sleeves G G, and elect an extension of the table to the limit ofthe screw-shafts S S; the turning of the crank being continued, the sleeves G G will also be turned out from their sleeves H H, and e'eet an extreme extension of the table, by carrying the pieces D D out from each other to the limited distance before determined. A reverse turning of the said crank W will contract the distance before extended; and, in either case, whether the said sleeves G and H and shaft S are used singly, as shown in iig. 3, or in pairs, as in iig.A 1, the result will be substantially lthe same; and, by using the devices in pairs, operated by the gears J and K, as described, a more perfect movement will hev secured, which is desirable.

The devices above described can be readily applied THOMAS C. ELLISON.

Witnesses ALEX. SELKIRK, CHARLES SELKIRK.

y as and for the purpose set. 

